Alto, California

Not to be confused with Alta, California.

Alto
Census-designated place
Location of Alto in Marin County, California.
Alto Location in California
Coordinates: 37°54′16″N122°31′32″W / 37.90444°N 122.52556°W / 37.90444; -122.52556
Country	United States
State	California
County	Marin County
Metro	San Francisco Bay Area
Area [1]
• Total	0.13 sq mi (0.33 km2)
• Land	0.13 sq mi (0.33 km2)
• Water	0.00 sq mi (0.00 km2)  0%
Elevation [2]	26 ft (8 m)
Population  (2020)
• Total	732
• Density	5,809.52/sq mi (2,247.56/km2)
Time zone	UTC-8 (Pacific (PST))
• Summer (DST)	UTC-7 (PDT)
GNIS feature ID	218191; 2582933
U.S. Geological Survey Geographic Names Information System: Alto, California; U.S. Geological Survey Geographic Names Information System: Alto, California

Alto (Spanish for "Tall") is a census-designated place ^[3] adjacent to Mill Valley in Marin County, California. ^[2] It lies at an elevation of 26 feet (8 m). ^[2] The population was 732 at the 2020 census.

Geography

According to the United States Census Bureau, the CDP covered an area of 0.326 square kilometers (0.126 sq mi), all of it land.

Demographics

Historical population

Census	Pop.	Note	%±
2010	711		—
2020	732		3.0%
U.S. Decennial Census [4] 1850–1870 [5] [6] 1880-1890 [7] 1900 [8] 1910 [9] 1920 [10] 1930 [11] 1940 [12] 1950 [13] 1960 [14] 1970 [15] 1980 [16] 1990 [17] 2000 [18] 2010 [19]

The 2020 United States census reported that Alto had a population of 732. The population density was 5,809.5 inhabitants per square mile (2,243.1/km²). The racial makeup of Alto was 80.3% White, 0.3% African American, 0.3% Native American, 4.4% Asian, 0.1% Pacific Islander, 3.6% from other races, and 11.1% from two or more races. Hispanic or Latino of any race were 7.8% of the population.

The whole population lived in households.

There were 294 households, out of which 34.0% included children under the age of 18, 51.0% were married-couple households, 5.8% were cohabiting couple households, 27.9% had a female householder with no partner present, and 15.3% had a male householder with no partner present. 28.9% of households were one person, and 9.5% were one person aged 65 or older. The average household size was 2.49. There were 193 families (65.6% of all households).

The age distribution was 24.5% under the age of 18, 4.9% aged 18 to 24, 23.2% aged 25 to 44, 33.3% aged 45 to 64, and 14.1% who were 65 years of age or older. The median age was 42.7 years. For every 100 females, there were 98.4 males.

There were 314 housing units at an average density of 2,492.1 units per square mile (962.2 units/km²), of which 294 (93.6%) were occupied. Of these, 52.7% were owner-occupied, and 47.3% were occupied by renters. ^{[20] [21]}

Education

The community is in the Mill Valley Elementary School District and the Tamalpais Union High School District. ^[22]

References

1. "2020 U.S. Gazetteer Files". United States Census Bureau. Retrieved October 30, 2021.
2. U.S. Geological Survey Geographic Names Information System: Alto, California
3. U.S. Geological Survey Geographic Names Information System: Alto, California
4. "Decennial Census by Decade". United States Census Bureau .
5. "1870 Census of Population - Population of Civil Divisions less than Counties - California - Almeda County to Sutter County" (PDF). United States Census Bureau .
6. "1870 Census of Population - Population of Civil Divisions less than Counties - California - Tehama County to Yuba County" (PDF). United States Census Bureau .
7. "1890 Census of Population - Population of California by Minor Civil Divisions" (PDF). United States Census Bureau .
8. "1900 Census of Population - Population of California by Counties and Minor Civil Divisions" (PDF). United States Census Bureau .
9. "1910 Census of Population - Supplement for California" (PDF). United States Census Bureau .
10. "1920 Census of Population - Number of Inhabitants - California" (PDF). United States Census Bureau .
11. "1930 Census of Population - Number and Distribution of Inhabitants - California" (PDF). United States Census Bureau .
12. "1940 Census of Population - Number of Inhabitants - California" (PDF). United States Census Bureau .
13. "1950 Census of Population - Number of Inhabitants - California" (PDF). United States Census Bureau .
14. "1960 Census of Population - General population Characteristics - California" (PDF). United States Census Bureau .
15. "1970 Census of Population - Number of Inhabitants - California" (PDF). United States Census Bureau .
16. "1980 Census of Population - Number of Inhabitants - California" (PDF). United States Census Bureau .
17. "1990 Census of Population - Population and Housing Unit Counts - California" (PDF). United States Census Bureau .
18. "2000 Census of Population - Population and Housing Unit Counts - California" (PDF). United States Census Bureau .
19. "2010 Census of Population - Population and Housing Unit Counts - California" (PDF). United States Census Bureau .
20. "Alto CDP, California; DP1: Profile of General Population and Housing Characteristics - 2020 Census of Population and Housing". US Census Bureau. Retrieved March 31, 2025.
21. "Alto CDP, California; P16: Household Type - 2020 Census of Population and Housing". US Census Bureau. Retrieved March 31, 2025.
22. "2020 CENSUS - SCHOOL DISTRICT REFERENCE MAP: Marin County, CA" (PDF). U.S. Census Bureau . Retrieved April 28, 2023. - Text list